Chemically amplified positive photoresist composition for thick film, thick-film photoresist laminated product, manufacturing method for thick-film resist pattern, and manufacturing method for connection terminal

ABSTRACT

A chemically amplified positive photoresist composition for thick film that is used for forming a thick-film photoresist layer with a film thickness of 10 to 150 μm on top of a support, comprising (A) a compound that generates acid on irradiation with active light or radiation, (B) a resin that displays increased alkali solubility under the action of acid, and (C) an alkali-soluble resin, wherein the component (B) comprises a resin formed from a copolymer containing a structural unit (b1) with a specific structure.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a chemically amplified positivephotoresist composition for thick film, a thick-film photoresistlaminated product, a manufacturing method for a thick-film resistpattern, and a manufacturing method for a connection terminal. Morespecifically, the present invention relates to a chemically amplifiedpositive photoresist composition for thick film, a thick-filmphotoresist laminated product, a manufacturing method for a thick-filmresist pattern, and a manufacturing method for a connection terminalwhich are ideal for use in the formation of connection terminals such asbumps or metal posts, and wiring patterns, during both the manufactureof circuit substrates, and the manufacture of electronic components suchas CSP (chip size packages) that are mounted on such circuit substrates.

2. Description of Related Art

Photofabrication, which is now the most widely used technique forprecision microprocessing, is a generic term describing the technologyused for manufacturing precision components such as semiconductorpackages by applying a photosensitive resin composition to the surfaceof a processing target to form a coating, patterning this coating usingphotolithography techniques, and then conducting chemical etching orelectrolytic etching, and/or electroforming based mainly aroundelectroplating, using the patterned coating as a mask.

Recently, reductions in the size of electronic equipment have lead tofurther developments in higher density packaging of semiconductorpackages, including multipin thin-film packaging, reductions in packagesize, two dimensional packaging techniques using flip-chip systems, andother improvements in packaging density based on three dimensionalpackaging techniques. In these types of high density packagingtechniques, connection terminals, including protruding electrodes(mounting terminals) such as bumps which protrude above the package, andmetal posts that connect rewiring extending from peripheral terminals onthe wafer with the mounting terminals, must be positioned on the surfaceof the substrate with very high precision.

The materials used in the above type of photofabrication are typicallythick-film photoresists. Thick-film photoresists are used for formingthick-film photoresist layers, and can be used, for example, in theformation of bumps or metal posts by a plating process. Bumps or metalposts can be formed, for example, by forming a thick-film photoresistlayer with a film thickness of approximately 20 μm on top of a support,exposing the photoresist layer through a predetermined mask pattern,developing the layer to form a resist pattern in which the portions forforming the bumps or metal posts have been selectively removed(stripped), embedding a conductor such as copper into the strippedportions (the resist-free portions) using plating, and then removing thesurrounding residual resist pattern.

Positive photosensitive resin compositions including a compoundcontaining a quinone diazide group have been disclosed as suitablethick-film photoresists for the formation of bumps or wiring (forexample, see patent reference 1).

On the other hand, chemically amplified photoresists including an acidgenerator are known as photosensitive resin compositions with evenbetter sensitivity than that provided by conventional positivephotosensitive resin compositions including a compound containing aquinone diazide group. The characteristic features of a chemicallyamplified photoresist are that on irradiation (exposure), acid isgenerated from the acid generator, diffusion of this acid is promoted bypost exposure baking, and the base resin or the like of the resincomposition then undergoes an acid-catalyzed reaction, thereby alteringthe alkali solubility of the reacted resin.

Chemically amplified photoresists include positive photoresists, inwhich irradiation causes alkali insoluble portions to become alkalisoluble, and negative photoresists, in which irradiation causes alkalisoluble portions to become alkali insoluble. Of these two types, aspositive photoresists, chemically amplified photoresist compositions forplating have already been disclosed (for example, see patent reference 2and patent reference 3).

Requirements for the type of thick-film photoresist compositiondescribed above include an ability to form a film thickness of at least10 μm, favorable adhesion to substrates, favorable resistance to theplating solution and favorable wetting characteristics in the platingsolution during the plating treatment used for forming bumps, goodconformation of the metal composition formed by the plating treatment tothe resist pattern shape, and an ability to easily strip the photoresistusing a stripping solution following the plating treatment. Furthermore,with advances in plating technology, multiple plating steps and platingsteps that require more severe conditions have become necessary, meaningthe photoresist also requires favorable resistance to the platingprocess itself, to enable it to withstand multiple plating steps.

(Patent Reference 1)

Japanese Unexamined Patent Application, First Publication No.2002-258479

(Patent Reference 2)

Japanese Unexamined Patent Application, First Publication No.2001-281862

(Patent Reference 3)

Japanese Unexamined Patent Application, First Publication No.2001-281863

However, when conventional chemically amplified photoresist compositionsdisclosed in the patent references 2 and 3 are used to produce athick-film resist layer, because the stress resistance of thephotoresist composition to the plating process is unsatisfactory, themetal layer obtained from the plating treatment tends to swell, makingit difficult to achieve a favorable pattern for the plated product.Furthermore, the resistance of the photoresist composition to theplating solution is also inadequate, with chips and cracks developing inthe resist either during the plating step or during the washing stepfollowing plating, making conducting multiple plating steps with thesame resist pattern essentially impossible (poor plating resistance).

Furthermore, with the photosensitive resin composition comprising acompound containing a naphthoquinone diazide group disclosed in thepatent reference 1, which displays superior plating resistance,improving the sensitivity is problematic.

SUMMARY OF THE INVENTION

The present invention takes the above problems associated with theconventional technology into consideration, with an object of providinga chemically amplified positive photoresist composition for thick film,which enables the formation of a plated product with a favorable andstable shape, displays excellent stress resistance, plating solutionresistance, and plating resistance, and is ideal for manufacturingconnection terminals and the like, as well as providing a thick-filmphotoresist laminated product, a manufacturing method for a thick-filmresist pattern that uses the laminated product, and a manufacturingmethod for a connection terminal.

As a result of intensive investigations aimed at achieving the aboveobject, the inventors of the present invention discovered that inpositive thick-film chemically amplified photoresist compositions, theobject described above could be achieved by using a resin containing astructural unit with a specific structure as the resin that displays anincrease in alkali solubility under the action of acid, and they werehence able to complete the present invention.

In other words, a first aspect of the present invention is a chemicallyamplified positive photoresist composition for thick film that is usedfor forming a thick-film photoresist layer with a film thickness of 10to 150 μm on top of a support, including (A) a compound that generatesacid on irradiation with active light or radiation, (B) a resin thatdisplays increased alkali solubility under the action of acid, and (C)an alkali-soluble resin, wherein the component (B) includes a resinformed from a copolymer containing a structural unit (b1) represented bya general formula (1) shown below:

(wherein, R¹ represents a hydrogen atom or a methyl group, R² representsa lower alkyl group, and X represents a group which, in combination withthe carbon atom bonded thereto, forms a hydrocarbon ring of 5 to 20carbon atoms).

The component (B) is preferably a resin comprising a copolymercontaining the above structural unit (b1), and a structural unit (b2)derived from a polymerizable compound containing an ether linkage.

The polymerizable compound containing an ether linkage (b2) ispreferably a compound represented by a general formula (7) shown below,or phenoxypolyethylene glycol (meth)acrylate, methoxypolypropyleneglycol (meth)acrylate, or tetrahydrofurfuryl (meth)acrylate.CH₂═C(R′)COO—(C_(m)H_(2m)—CHR¹⁰—O)_(n)—R″  (7)(wherein, R′ represents a hydrogen atom or a methyl group, R¹⁰represents a hydrogen atom or an alkyl group of 1 or 2 carbon atoms, R″represents an alkyl group or aryl group of 1 to 7 carbon atoms that mayalso contain an oxygen atom, m represents an integer of either 1 or 2,and n represents an integer from 1 to 10.)

Relative to 100 parts by weight of the combined weight of the component(B) and the component (C), the quantity of the component (A) ispreferably within a range from 0.1 to 20 parts by weight, the quantityof the component (B) is preferably within a range from 5 to 95 parts byweight, and the quantity of the component (C) is preferably within arange from 5 to 95 parts by weight.

The component (C) preferably includes at least one resin selected from agroup consisting of (c1) novolak resins, (c2) copolymers containing ahydroxystyrene structural unit and a styrene structural unit, (c3)acrylic resins, and (c4) vinyl resins.

A chemically amplified positive photoresist composition for thick filmaccording to this first aspect may also include an acid diffusioncontrol agent (D).

A second aspect of the present invention is a thick-film photoresistlaminated product comprising a support, and a thick-film photoresistlayer with a film thickness of 10 to 150 μm, formed from a chemicallyamplified positive photoresist composition for thick film according tothe first aspect, laminated on top of the support.

The film thickness of this thick-film photoresist layer is preferablywithin a range from 20 to 120 μm.

A third aspect of the present invention is a manufacturing method for athick-film resist pattern, including a lamination step for producing athick-film photoresist laminated product according to the second aspect,an exposure step for selectively irradiating the thick-film photoresistlaminated product with active light or radiation, and a developing stepfor conducting post exposure developing to produce a thick-film resistpattern.

A fourth aspect of the present invention is a manufacturing method for aconnection terminal, including a step for forming a connection terminalformed from a conductor on a resist-free portion of the thick-filmresist pattern produced using the manufacturing method for a thick-filmresist pattern according to the third aspect.

The depth of the resist-free portion is preferably within a range from10 to 150 μm, and even more preferably from 20 to 120 μm.

This resist-free portion describes the portion for forming bumps andmetal posts that has been selectively removed (stripped) duringdeveloping of the exposed thick-film photoresist laminated product.

The term “structural unit” refers to a monomer unit used in producing apolymer. Furthermore, the term (meth)acrylic acid is a generic term forboth methacrylic acid and acrylic acid.

Similarly, (meth)acrylate is a generic term for both acrylate andmethacrylate.

The present invention provides a chemically amplified positivephotoresist composition for thick film, which enables the formation of aplated product with a favorable shape, displays excellent platingresistance and a high level of contrast, and is ideal for manufacturingconnection terminals and the like, as well as providing a thick-filmphotoresist laminated product, a manufacturing method for a thick-filmresist pattern that uses the laminated product, and a manufacturingmethod for a connection terminal.

Using a chemically amplified positive photoresist composition for thickfilm of the first aspect of the present invention enables particularlyfavorable formation of resist patterns with aspect ratios of 2 orgreater, and this enables the formation of resist-free patterns(resist-free portions) with aspect ratios of 2 or greater. Using achemically amplified positive photoresist composition for thick filmaccording to the first aspect of the present invention even enables theformation of resist patterns with an aspect ratio of 10, and resist-freepatterns (resist-free portions) based on such resist patterns.

DETAILED DESCRIPTION OF THE INVENTION

As follows is a detailed description of the present invention.

A chemically amplified positive photoresist composition for thick filmaccording to the present invention is a composition used for forming athick-film photoresist layer with a film thickness of 10 to 150 μm ontop of a support, and includes (A) a compound that generates acid onirradiation with active light or radiation, (B) a resin that displaysincreased alkali solubility under the action of acid, and (C) analkali-soluble resin, wherein the component (B) includes a resin formedfrom a copolymer containing a structural unit (b1) represented by ageneral formula (1) shown above.

First is a description of the compound (A) that generates acid onirradiation with active light or radiation.

The compound (A) that generates acid on irradiation with active light orradiation in the present invention (hereafter referred to as thecomponent (A)) is an acid generator, and there are no particularrestrictions on the compound, provided it generates acid, eitherdirectly or indirectly, on irradiation.

Specific examples of the component (A) include halogen-containingtriazine compounds such as2,4-bis(trichloromethyl)-6-piperonyl-1,3,5-triazine,2,4-bis(trichloromethyl)-6-[2-(2-furyl)ethenyl]-s-triazine,2,4-bis(trichloromethyl)-6-[2-(5-methyl-2-furyl)ethenyl]-s-triazine,2,4-bis(trichloromethyl)-6-[2-(5-ethyl-2-furyl)ethenyl]-s-triazine,2,4-bis(trichloromethyl)-6-[2-(5-propyl-2-furyl)ethenyl]-s-triazine,2,4-bis(trichloromethyl)-6-[2-(3,5-dimethoxyphenyl)ethenyl]-s-triazine,2,4-bis(trichloromethyl)-6-[2-(3,5-diethoxyphenyl)ethenyl]-s-triazine,2,4-bis(trichloromethyl)-6-[2-(3,5-dipropoxyphenyl)ethenyl]-s-triazine,2,4-bis(trichloromethyl)-6-[2-(3-methoxy-5-ethoxyphenyl)ethenyl]-s-triazine,2,4-bis(trichloromethyl)-6-[2-(3-methoxy-5-propoxyphenyl)ethenyl]-s-triazine,2,4-bis(trichloromethyl)-6-[2-(3,4-methylenedioxyphenyl)ethenyl]-s-triazine,2,4-bis(trichloromethyl)-6-(3,4-methylenedioxyphenyl)-s-triazine,2,4-bis-trichloromethyl-6-(3-bromo-4-methoxy)phenyl-s-triazine,2,4-bis-trichloromethyl-6-(2-bromo-4-methoxy)phenyl-s-triazine,2,4-bis-trichloromethyl-6-(2-bromo-4-methoxy)styrylphenyl-s-triazine,2,4-bis-trichloromethyl-6-(3-bromo-4-methoxy)styrylphenyl-s-triazine,2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-1,3,5-triazine,2-(4-methoxynaphthyl)-4,6-bis(trichloromethyl)-1,3,5-triazine,2-[2-(2-furyl)ethenyl]-4,6-bis(trichloromethyl)-1,3,5-triazine,2-[2-(5-methyl-2-furyl)ethenyl]-4,6-bis(trichloromethyl)-1,3,5-triazine,2-[2-(3,5-dimethoxyphenyl)ethenyl]-4,6-bis(trichloromethyl)-1,3,5-triazine,2-[2-(3,4-dimethoxyphenyl)ethenyl]-4,6-bis(trichloromethyl)-1,3,5-triazine,2-(3,4-methylenedioxyphenyl)-4,6-bis(trichloromethyl)-1,3,5-triazine,tris(1,3-dibromopropyl)-1,3,5-triazine, andtris(2,3-dibromopropyl)-1,3,5-triazine, and tris(2,3-dibromopropyl)isocyanurate represented by a general formula (2) shown below such ashalogen-containing triazine compounds.

(wherein, R³ to R⁵ may be either the same or different, and eachrepresents a halogenated alkyl group) Other specific examples of thecomponent (A) include α-(p-toluenesulfonyloxyimino)-phenylacetonitrile,α-(benzenesulfonyloxyimino)-2,4-dichlorophenylacetonitrile,α-(benzenesulfonyloxyimino)-2,6-dichlorophenylacetonitrile,α-(2-chlorobenzenesulfonyloxyimino)-4-methoxyphenylacetonitrile,α-(ethylsulfonyloxyimino)-1-cyclopentenylacetonitrile, and compoundsrepresented by a general formula (3) shown below.

(wherein, R⁶ represents a monovalent to trivalent organic group, R⁷represents a substituted or unsubstituted saturated hydrocarbon group,unsaturated hydrocarbon group, or aromatic compound group, and nrepresents a natural number within a range from 1 to 3.)

Here, the term “aromatic compound group” refers to a group formed from acompound that shows the characteristic physical and chemical propertiesof an aromatic compound, and specific examples include aromatichydrocarbon groups such as a phenyl group or naphthyl group, andheterocyclic groups such as a furyl group or thienyl group. These groupsmay also include suitable substituents on the ring, including one ormore halogen atoms, alkyl groups, alkoxy groups, or nitro groups.Compounds in which R⁶ represents an aromatic compound group, and R⁷represents a lower alkyl group are preferred. Furthermore, as the groupR⁷, alkyl groups of 1 to 4 carbon atoms are particularly preferred,including a methyl group, ethyl group, propyl group, and butyl group.Examples of the acid generators represented by the above generalformula, in the case where n=1, include compounds in which R⁶ is aphenyl group, a methylphenyl group or a methoxyphenyl group, and R⁷ is amethyl group, namely, α-(methylsulfonyloxyimino)-1-phenylacetonitrile,α-(methylsulfonyloxyimino)-1-(p-methylphenyl)acetonitrile, andα-(methylsulfonyloxyimino)-1-(p-methoxyphenyl)acetonitrile. In the casewhere n=2, specific examples of the acid generators represented by theabove general formula include the acid generators represented by thechemical formulas shown below.

Additional specific examples of the component (A) includebissulfonyldiazomethanes such as bis(p-toluenesulfonyl)diazomethane,bis(1, 1-dimethylethylsulfonyl)diazomethane,bis(cyclohexylsulfonyl)diazomethane, andbis(2,4-dimethylphenylsulfonyl)diazomethane; nitrobenzyl derivativessuch as 2-nitrobenzyl p-toluenesulfonate, 2,6-nitrobenzylp-toluenesulfonate, nitrobenzyl tosylate, dinitrobenzyl tosylate,nitrobenzyl sulfonate, nitrobenzyl carbonate, and dinitrobenzylcarbonate; sulfonic acid esters such as pyrogallol trimesylate,pyrogallol tritosylate, benzyl tosylate, benzyl sulfonate,N-methylsulfonyloxysuccinimide, N-trichloromethylsulfonyloxysuccinimide,N-phenylsulfonyloxymaleimide, and N-methylsulfonyloxyphthalimide;trifluoromethanesulfonic acid esters of N-hydroxyphthalimide andN-hydroxynaphthalimide; onium salts such as diphenyliodoniumhexafluorophosphate, (4-methoxyphenyl)phenyliodoniumtrifluoromethanesulfonate, bis(p-tert-butylphenyl)iodoniumtrifluoromethanesulfonate, triphenylsulfonium hexafluorophosphate,(4-methoxyphenyl)diphenylsulfonium trifluoromethanesulfonate, and(p-tert-butylphenyl)diphenylsulfonium trifluoromethanesulfonate; benzointosylates such as benzoin tosylate and α-methylbenzoin tosylate; andother diphenyliodonium salts, triphenylsulfonium salts, phenyldiazoniumsalts, and benzyl carbonate.

Of these compounds, preferred compounds for the component (A) includecompounds containing at least two oxime sulfonate groups represented bya general formula (4) shown below:R—SO₂O—N═C(CN)—  (4)(wherein, R represents a substituted or unsubstituted alkyl group oraryl group of, for example, 1 to 8 carbon atoms), and of these,compounds represented by a general formula (5) shown below areparticularly preferred.R—SO₂O—N═C(CN)-A-C(CN)═N—OSO₂—R  (5)(wherein, A represents a bivalent, substituted or unsubstituted alkylenegroup of 1 to 8 carbon atoms, or a bivalent aromatic compound group, andR represents a substituted or unsubstituted alkyl group or aryl groupof, for example, 1 to 8 carbon atoms). Here, the term “aromatic compoundgroup” refers to a group formed from a compound that shows thecharacteristic physical and chemical properties of an aromatic compound,and specific examples include aromatic hydrocarbon groups such as aphenyl group or naphthyl group, and heterocyclic groups such as a furylgroup or thienyl group. These groups may also include suitablesubstituents on the ring, including one or more halogen atoms, alkylgroups, alkoxy groups, or nitro groups. Compounds of the above generalformula in which A represents a phenylene group and R represents, forexample, a lower alkyl group of 1 to 4 carbon atoms are particularlydesirable.

This component (A) can use either a single compound, or a combination oftwo or more different compounds. The blend quantity of the component (A)is typically within a range from 0.1 to 20 parts by weight, andpreferably from 0.2 to 10 parts by weight, per 100 parts by weight ofthe combined weight of the component (B) and the component (C). Byensuring this quantity is at least 0.1 parts by weight, satisfactorysensitivity can be achieved, and by ensuring the quantity is no morethan 20 parts by weight, a favorable solubility is achieved in thesolvent, enabling the formation of a homogeneous solution, which tendsto improve the storage stability.

Next is a description of the aforementioned resin (B) that displaysincreased alkali solubility under the action of acid.

The resin (B) that displays increased alkali solubility under the actionof acid in the present invention (hereafter referred to as the component(B)) includes a resin formed from a copolymer containing (b 1) astructural unit (hereafter referred to as a unit (b1)) represented by ageneral formula (1) shown below:

(wherein, R¹ represents a hydrogen atom or a methyl group, R² representsa lower alkyl group, and X represents a group which, in combination withthe carbon atom bonded thereto, forms a hydrocarbon ring of 5 to 20carbon atoms).

As follows is a description of the unit (b1).

The unit (b1) is a structural unit represented by the general formula(1) shown above.

In the general formula (1), R¹ represents either a hydrogen atom or amethyl group.

The lower alkyl group represented by R² may be either a straight chaingroup or a branched group, and suitable examples include a methyl group,ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutylgroup, sec-butyl group, tert-butyl group, and any of the various pentylgroups. Of these, from the viewpoints of achieving a high level ofcontrast, and favorable resolution and depth of focus values and thelike, a lower alkyl group of 2 to 4 carbon atoms is particularlydesirable.

Furthermore, X represents a group which, in combination with the carbonatom bonded thereto, forms a monocyclic or polycyclic hydrocarbon ringsystem of 5 to 20 carbon atoms.

Examples of monocyclic hydrocarbon rings include cyclopentane,cyclohexane, cycloheptane, and cyclooctane.

Examples of polycyclic hydrocarbon ring systems include bicyclichydrocarbon ring systems, tricyclic hydrocarbon ring systems, andtetracyclic hydrocarbon ring systems. Specific examples includepolycyclic hydrocarbon ring systems such as adamantane, norbornane,isobornane, tricyclodecane, and tetracyclododecane.

Of these, particularly preferred forms of X, which represents a groupwhich, in combination with the carbon atom bonded thereto, forms amonocyclic or polycyclic hydrocarbon ring system of 5 to 20 carbonatoms, are a cyclohexane ring and an adamantane ring system.

Specific examples of preferred forms of the structural unit representedby the above general formula (1) include the structural units shownbelow.

As the unit (b1), either a single structural unit represented by thegeneral formula (1) can be used, or alternatively, two or morestructural units with different structures can be used.

In addition, the component (B) is preferably a resin comprising acopolymer containing the above structural unit (b1), and a structuralunit (b2) derived from a polymerizable compound containing an etherlinkage. By incorporating the component (b2), the adhesion with thesubstrate during developing can be improved, and a more favorableplating solution resistance is achieved.

As follows is a description of the unit (b2).

The unit (b2) is a structural unit derived from a polymerizable compoundcontaining an ether linkage.

Examples of this polymerizable compound containing an ether linkageinclude compounds represented by a general formula (7) shown below, aswell as phenoxypolyethylene glycol (meth)acrylate, methoxypolypropyleneglycol (meth)acrylate, and tetrahydrofurfuryl (meth)acrylate.CH₂═C(R′)COO—(C_(m)H₂, —CHR¹⁰—O)_(n)—R″  (7)(wherein, R′ represents a hydrogen atom or a methyl group, R¹⁰represents a hydrogen atom or an alkyl group of 1 or 2 carbon atoms, R″represents an alkyl group or aryl group of 1 to 7 carbon atoms that mayalso contain an oxygen atom, m represents an integer of either 1 or 2,and n represents an integer from 1 to 10.)

Specific examples of the polymerizable compound containing an etherlinkage include radical polymerizable compounds, including (meth)acrylicacid derivatives containing both an ether linkage and an ester linkagesuch as 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate,methoxytriethylene glycol (meth)acrylate, 3-methoxybutyl (meth)acrylate,ethylcarbitol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate,methoxypolypropylene glycol (meth)acrylate, and tetrahydrofurfuryl(meth)acrylate. Of these, 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl(meth)acrylate, and methoxytriethylene glycol (meth)acrylate arepreferred. These compounds can be used either singularly, or incombinations of two or more different compounds.

In addition, for the purposes of controlling certain physical andchemical properties, the component (B) may also contain structural unitsderived from other polymerizable compounds. Here, the term “otherpolymerizable compound” means polymerizable compounds other than themonomers that give rise to the aforementioned structural unit (b1) andstructural unit (b2). Such polymerizable compounds include known radicalpolymerizable compounds and anionic polymerizable compounds. Specificexamples include radical polymerizable compounds, includingmonocarboxylic acids such as acrylic acid, methacrylic acid, andcrotonic acid, dicarboxylic acids such as maleic acid, fumaric acid, anditaconic acid, methacrylic acid derivatives containing both a carboxylgroup and an ester linkage such as 2-methacryloyloxyethylsuccinic acid,2-methacryloyloxyethylmaleic acid, 2-methacryloyloxyethylphthalic acid,and 2-methacryloyloxyethylhexahydrophthalic acid; alkyl (meth)acrylatessuch as methyl (meth)acrylate, ethyl (meth)acrylate, and butyl(meth)acrylate; hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl(meth)acrylate and 2-hydroxypropyl (meth)acrylate; aryl (meth)acrylatessuch as phenyl (meth)acrylate and benzyl (meth)acrylate; diesters ofdicarboxylic acids such as diethyl maleate and dibutyl fumarate; vinylgroup-containing aromatic compounds such as styrene, α-methylstyrene,chlorostyrene, chloromethylstyrene, vinyltoluene, hydroxystyrene,α-methylhydroxystyrene, and α-ethylhydroxystyrene; vinylgroup-containing aliphatic compounds such as vinyl acetate; conjugateddiolefins such as butadiene and isoprene; nitrile group-containingpolymerizable compounds such as acrylonitrile and methacrylonitrile;chlorine-containing polymerizable compounds such as vinyl chloride andvinylidene chloride; and amide bond-containing polymerizable compoundssuch as acrylamide and methacrylamide.

The quantity of the unit (b1) within the component (B) is preferablywithin a range from 10 to 90% by weight, and even more preferably from30 to 70% by weight. If this quantity exceeds 90% by weight, then thesensitivity tends to fall, whereas if the quantity is less than 10% byweight, then the residual film ratio tends to decrease.

The quantity of the unit (b2) within the component (B) is preferablywithin a range from 10 to 90% by weight, and even more preferably from30 to 70% by weight. If this quantity exceeds 90% by weight, then theresidual film ratio tends to decrease, whereas if the quantity is lessthan 10% by weight, then the adhesion with the substrate duringdeveloping, and the plating solution resistance tend to deteriorate.

Furthermore, the polystyrene equivalent weight average molecular weight(hereafter referred to as the weight average molecular weight) of thecomponent (B) is preferably within a range from 10,000 to 600,000, andeven more preferably from 50,000 to 600,000, and most preferably from230,000 to 550,000. If the weight average molecular weight exceeds600,000, then the strippability deteriorates. In contrast, if the weightaverage molecular weight is less than 10,000, then the resist film doesnot attain sufficient strength, increasing the danger of blistering orcracking of the resist profile during plating. Furthermore, if theweight average molecular weight is less than 230,000, then theresistance to cracking tends to deteriorate.

As a result of containing the unit (b1), the component (B) displays alarge change in alkali solubility on exposure (a high level ofcontrast).

In addition, the component (B) is preferably a resin with a degree ofdispersion of at least 1.05. In this description, the degree ofdispersion describes the value obtained by dividing the weight averagemolecular weight by the number average molecular weight. If the degreeof dispersion is less than 1.05, then the stress resistance to platingweakens, and the metal layer produced by the plating treatment tends tobe undesirably prone to swelling.

The blend quantity of the component (B) is typically within a range from5 to 95 parts by weight, and preferably from 10 to 90 parts by weight,per 100 parts by weight of the combined weight of the component (B) andthe component (C). By ensuring this blend quantity is at least 5 partsby weight, cracking becomes far less likely during plating, whereasensuring the quantity is no more than 95 parts by weight tends toprovide a favorable improvement in the sensitivity.

Next is a description of the alkali-soluble resin (C).

As the alkali-soluble resin (C) (referred to as the component (C)) usedin a chemically amplified positive photoresist composition for thickfilm according to the present invention, resins selected from amongstknown resins commonly used as alkali-soluble resins in conventionalchemically amplified photoresists can be used. Of such resins, thosecontaining at least one resin selected from a group consisting of (c1)novolak resins, (c2) copolymers containing a hydroxystyrene structuralunit and a styrene structural unit, (c3) acrylic resins, and (c4) vinylresins are preferred, and resins containing a novolak resin (c1) and/ora copolymer (c2) containing a hydroxystyrene structural unit and astyrene structural unit are particularly preferred. The reason for thispreference is that such resins facilitate better control of thecoatability and the developing rate.

First is a description of the novolak resin (c1).

The novolak resin of the component (c1) is typically obtained by anaddition condensation of an aromatic compound with a phenolic hydroxylgroup (hereafter, simply referred to as a phenol) and an aldehyde, inthe presence of an acid catalyst.

Examples of the phenol used include phenol, o-cresol, m-cresol,p-cresol, o-ethylphenol, m-ethylphenol, p-ethylphenol, o-butylphenol,m-butylphenol, p-butylphenol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol,2,6-xylenol, 3,4-xylenol, 3,5-xylenol, 2,3,5-trimethylphenol,3,4,5-trimethylphenol, p-phenylphenol, resorcinol, hydroquinone,hydroquinone monomethyl ether, pyrogallol, fluoroglucinol,hydroxydiphenyl, bisphenol A, gallic acid, gallic esters, α-naphthol,and β-naphthol.

Furthermore, examples of the aldehyde include formaldehyde, furfural,benzaldehyde, nitrobenzaldehyde, and acetaldehyde.

There are no particular restrictions on the catalyst used in theaddition condensation, and suitable acid catalysts include hydrochloricacid, nitric acid, sulfuric acid, formic acid, oxalic acid, and aceticacid.

Novolak resins that use solely m-cresol as the phenol displayparticularly favorable developing profiles, and are consequentlypreferred.

Next is a description of the above copolymer (c2) containing ahydroxystyrene structural unit and a styrene structural unit.

The component (c2) used in the present invention is a copolymer thatcontains at least a hydroxystyrene structural unit and a styrenestructural unit. This includes copolymers comprising only hydroxystyrenestructural units and styrene structural units, as well as copolymerscomprising hydroxystyrene structural units, styrene structural units,and other, different structural units.

Examples of the hydroxystyrene structural unit include hydroxystyrenestructural units derived from hydroxystyrenes such as p-hydroxystyrene,or from α-alkylhydroxystyrenes such as α-methylhydroxystyrene andα-ethylhydroxystyrene.

Examples of the styrene structural unit include structural units derivedfrom styrene, chlorostyrene, chloromethylstyrene, vinyltoluene, andα-methylstyrene.

Next is a description of the acrylic resin (c3).

There are no particular restrictions on the acrylic resin of thecomponent (c3), provided it is an alkali-soluble acrylic resin, althoughacrylic resins comprising a structural unit derived from a polymerizablecompound containing an ether linkage, and a structural unit derived froma polymerizable compound containing a carboxyl group are particularlypreferred.

Examples of polymerizable compounds containing an ether linkage include(meth)acrylic acid derivatives containing both an ether linkage and anester linkage such as 2-methoxyethyl (meth)acrylate, methoxytriethyleneglycol (meth)acrylate, 3-methoxybutyl (meth)acrylate, ethylcarbitol(meth)acrylate, phenoxypolyethylene glycol (meth)acrylate,methoxypolypropylene glycol (meth)acrylate, and tetrahydrofurfuryl(meth)acrylate, and of these, 2-methoxyethyl (meth)acrylate andmethoxytriethylene glycol (meth)acrylate are preferred. These compoundscan be used either singularly, or in combinations of two or moredifferent compounds.

Examples of polymerizable compounds containing a carboxyl group includemonocarboxylic acids such as acrylic acid, methacrylic acid, andcrotonic acid, dicarboxylic acids such as maleic acid, fumaric acid, anditaconic acid, and compounds containing both a carboxyl group and anester linkage such as 2-methacryloyloxyethylsuccinic acid,2-methacryloyloxyethylmaleic acid, 2-methacryloyloxyethylphthalic acid,and 2-methacryloyloxyethylhexahydrophthalic acid. Of these, acrylic acidand methacrylic acid are preferred. These compounds can be used eithersingularly, or in combinations of two or more different compounds.

Next is a description of the vinyl resin (c4).

The vinyl resin of the component (c4) is a poly(vinyl low alkyl ether),and comprises a (co)polymer produced by polymerizing either a singlevinyl low alkyl ether represented by a general formula (6) shown below,or a mixture of two or more such ethers.

(wherein in the general formula (6), R⁸ represents a straight chain orbranched alkyl group of 1 to 5 carbon atoms.)

In the general formula (6), examples of the straight chain or branchedalkyl group of 1 to 5 carbon atoms include a methyl group, ethyl group,n-propyl group, i-propyl group, n-butyl group, i-butyl group, n-pentylgroup, and i-pentyl group. Of these alkyl groups, a methyl group, ethylgroup, or i-butyl group is preferred, and a methyl group is particularlydesirable. In the present invention, poly (vinyl methyl ether) is aparticularly preferred poly(vinyl low alkyl ether).

The blend quantity of the component (C) is typically within a range from5 to 95 parts by weight, and preferably from 10 to 90 parts by weight,per 100 parts by weight of the combined weight of the component (B) andthe component (C). By ensuring this blend quantity is at least 5 partsby weight, cracking resistance can be improved, whereas ensuring thequantity is no more than 95 parts by weight tends to prevent thicknessloss during developing.

As follows is a description of the acid diffusion control agent (D).

In a chemically amplified positive photoresist composition for thickfilm according to the present invention, an acid diffusion control agent(D) (hereafter referred to as the component (D)) is preferably added toimprove the resist pattern shape, and the post exposure stability of thelatent image formed by the pattern-wise exposure of the resist layer.

As the component (D), any of the known compounds typically used as aciddiffusion control agents in conventional chemically amplified resistscan be selected and used. Incorporating a nitrogen-containing compound(d1) within the component (D) is particularly preferred, and wherenecessary, (d2) an organic carboxylic acid, a phosphorus oxo acidcompound, or a derivative thereof can also be included.

Next is a description of the above nitrogen-containing compound (d1).

Examples of the nitrogen-containing compound of the component (d1)include trimethylamine, diethylamine, triethylamine, di-n-propylamine,tri-n-propylamine, tribenzylamine, diethanolamine, triethanolamine,n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine,ethylenediamine, N,N,N′,N′-tetramethylethylenediamine,tetramethylenediamine, hexamethylenediamine,4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl ether,4,4′-diaminobenzophenone, 4,4′-diaminodiphenylamine, formamide,N-methylformamide, N,N-dimethylformamide, acetamide, N-methylacetamide,N,N-dimethylacetamide, propionamide, benzamide, pyrrolidone,N-methylpyrrolidone, methylurea, 1,1-dimethylurea, 1,3-dimethylurea,1,1,3,3-tetramethylurea, 1,3-diphenylurea, imidazole, benzimidazole,4-methylimidazole, 8-oxyquinoline, acridine, purine, pyrrolidine,piperidine, 2,4,6-tri(2-pyridyl)-s-triazine, morpholine,4-methylmorpholine, piperazine, 1,4-dimethylpiperazine, and1,4-diazabicyclo[2.2.2]octane.

Of these, alkanolamines such as triethanolamine are particularlypreferred.

These compounds can be used either singularly, or in combinations of twoor more different compounds.

The component (d1) is typically used in quantities within a range from 0to 5% by weight, and preferably from 0 to 3% by weight, relative to avalue of 100% by weight for the combination of the component (B) and thecomponent (C).

Next is a description of the organic carboxylic acid, phosphorus oxoacid compound, or derivative thereof of the aforementioned component(d2).

As the organic carboxylic acid, acids such as malonic acid, citric acid,malic acid, succinic acid, benzoic acid, and salicylic acid are ideal,and salicylic acid is particularly desirable.

Examples of the phosphorus oxo acid compound or derivative thereofinclude phosphoric acid or derivatives thereof such as esters, includingphosphoric acid, di-n-butyl phosphate, and diphenyl phosphate;phosphonic acid or derivatives thereof such as esters, includingphosphonic acid, dimethyl phosphonate, di-n-butyl phosphonate,phenylphosphonic acid, diphenyl phosphonate, and dibenzyl phosphonate;and phosphinic acid or derivatives thereof such as esters, includingphosphinic acid and phenylphosphinic acid. Of these, phosphonic acid isparticularly desirable.

These compounds can be used either singularly, or in combinations of twoor more different compounds.

The component (d2) is typically used in quantities within a range from 0to 5% by weight, and preferably from 0 to 3% by weight, relative to avalue of 100% by weight for the combination of the component (B) and thecomponent (C).

Furthermore, the component (d2) is preferably used in the same quantityas the component (d1). The reason for this requirement is that thecomponent (d2) and the component (d1) are stabilized through theformation of a mutual salt.

Other conventional miscible additives can also be added to a chemicallyamplified positive photoresist composition for thick film of the presentinvention according to need, provided such addition does not impair theintrinsic characteristics of the present invention, and examples of suchmiscible additives include additive resins for improving the propertiesof the resist film, plasticizers, adhesion assistants, stabilizers,colorants, and surfactants.

In addition, a chemically amplified positive photoresist composition forthick film of the present invention may also include a suitable quantityof an organic solvent for the purposes of regulating the compositionviscosity. Specific examples of this organic solvent include ketonessuch as acetone, methyl ethyl ketone, cyclohexanone, methyl isoamylketone and 2-heptanone; polyhydric alcohols and derivatives thereof suchas ethylene glycol, ethylene glycol monoacetate, diethylene glycol,diethylene glycol monoacetate, propylene glycol, propylene glycolmonoacetate, dipropylene glycol, or the monomethyl ether, monoethylether, monopropyl ether, monobutyl ether or monophenyl ether ofdipropylene glycol monoacetate; cyclic ethers such as dioxane; andesters such as methyl lactate, ethyl lactate, methyl acetate, ethylacetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methylmethoxypropionate, and ethyl ethoxypropionate. These organic solventscan be used singularly, or as a mixed solvent of two or more differentsolvents.

The quantity used of such solvents, for example in the case in whichspin coating is used to form a thick film of at least 10 μm, ispreferably sufficient to produce a solid fraction concentration for thechemically amplified positive photoresist composition for thick filmthat falls within a range from 30 to 65% by weight. If this solidfraction concentration is less than 30% by weight, then producing a filmthickness that is ideal for the manufacture of a connection terminalbecomes problematic, whereas if the solid fraction concentration exceeds65% by weight, then the fluidity of the composition worsens markedly,making handling difficult, and also making it difficult to achieve auniform resist film using spin coating methods.

Preparation of a chemically amplified positive photoresist compositionfor thick film according to the present invention may be conducted bysimply mixing and stirring together each of the components describedabove using normal methods, or if necessary, by dispersing and mixingthe components using a dispersion device such as a dissolver, ahomogenizer, or a three roll mill. Furthermore, following mixing of thecomponents, the composition may also be filtered using a mesh or amembrane filter or the like.

A chemically amplified positive photoresist composition for thick filmof the present invention is ideal for forming a thick-film photoresistlayer with a film thickness of 10 to 150 μm, and preferably from 20 to120 μm, and even more preferably from 20 to 80 μm, on the surface of asupport.

A thick-film photoresist laminated product of the present inventionincludes a support, and a thick-film photoresist layer, formed from anaforementioned chemically amplified positive photoresist composition forthick film, laminated on top of the support.

As the support used in the present invention, conventional supports canbe used without any particular restrictions, and suitable examplesinclude substrates for electronic componentry, as well as substrates onwhich a predetermined wiring pattern has already been formed. Specificexamples of suitable substrates include metal-based substrates such assilicon, silicon nitride, titanium, tantalum, palladium,titanium-tungsten, copper, chrome, iron, and aluminum, as well as glasssubstrates. Suitable materials for the wiring pattern include copper,solder, chrome, aluminum, nickel, and gold.

The thick-film photoresist laminated product described above can bemanufactured using the method described below for example.

Namely, a solution of a chemically amplified positive photoresistcomposition for thick film prepared in the manner described above isapplied to a support, and heating is used to remove the solvent and formthe desired coating. The application of the solution to the support canbe conducted using a method such as spin coating, slit coating, rollcoating, screen printing, or an applicator-based method. The prebakeconditions used for a coating of a composition of the present inventionvary depending on factors such as the nature of each of the componentswithin the composition, the blend proportions used, and the thicknesswith which the composition is applied, although typical conditionsinvolve heating at 70 to 150° C., and preferably at 80 to 140° C., for aperiod of 2 to 60 minutes.

The film thickness of a thick-film photoresist layer of the presentinvention is typically within a range from 10 to 150 μm, and preferablyfrom 20 to 120 μm, and even more preferably from 20 to 80 μm.

Subsequently, in order to form a resist pattern using the thus producedthick-film photoresist laminated product, the thick-film photoresistlayer is selectively irradiated (exposed), through a mask with apredetermined pattern, with active light or radiation, such asultraviolet light of wavelength 300 to 500 nm or visible light.

In this description, “active light” describes light rays that activatethe acid generator, thus causing the generation of acid. As the lightsource for the active light or radiation, a low pressure mercury lamp,high pressure mercury lamp, ultra high pressure mercury lamp, metalhalide lamp, or argon gas laser or the like can be used. In thisdescription, the term “radiation” refers to ultraviolet radiation,visible light, far ultraviolet radiation, X-rays, electron beams, andion beams and the like. The radiation exposure dose varies depending onthe nature of each of the components within the composition, the blendproportions used, and the thickness of the coating, although in thosecases where a ultra high pressure mercury lamp is used, a typicalexposure dose is within a range from 100 to 10,000 mJ/cm².

Subsequently, following exposure, the laminated product is heated usingconventional methods, to promote diffusion of the acid and alter thealkali solubility of the exposed portions of the thick-film photoresistlayer.

Using a predetermined aqueous alkali solution as the developingsolution, the unnecessary portions of the resist layer are thendissolved and removed, thus yielding a predetermined resist pattern.Suitable examples of the developing solution include aqueous solutionsof alkali materials such as sodium hydroxide, potassium hydroxide,sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia,ethylamine, n-propylamine, diethylamine, di-n-propylamine,triethylamine, methyldiethylamine, dimethylethanolamine,triethanolamine, tetramethylammonium hydroxide, tetraethylammoniumhydroxide, pyrrole, piperidine, 1,8-diazabicyclo[5,4,0]-7-undecene, and1,5-diazabicyclo[4,3,0]-5-nonane. An aqueous solution prepared by addinga water-soluble organic solvent such as methanol or ethanol, or asurfactant to the aqueous solution of any of these alkali compounds mayalso be used as the developing solution.

The developing time varies depending on the nature of each of thecomponents within the composition, the blend proportions used, and thedried film thickness of the composition, but is typically within a rangefrom 1 to 30 minutes. Furthermore, suitable methods for the developingprocess include spin methods, dipping methods, puddle methods, and spraydeveloping methods. Following developing, the structure is washed underrunning water for 30 to 90 seconds, and is then dried using an air gunor an oven or the like.

Connection terminals such as metal posts and bumps can then be formed byusing plating or the like to embed a conductor formed from a metal orthe like within the resist-free portions (the portions removed by thealkali developing solution) of the thus obtained resist pattern. Thereare no particular restrictions on the plating method, and anyconventional plating method can be used. As the plating solution, asolder plating solution, copper plating solution, gold plating solution,or nickel plating solution can be favorably used.

Finally, the remaining resist pattern is removed in accordance withconventional methods, using a stripping solution or the like.

EXAMPLES

As follows is a description of examples of the present invention,although these examples in no way limit the scope of the invention.Unless specified otherwise, “parts” refers to parts by weight, and %values refer to weight % values.

Synthesis Example 1

<Synthesis of (B-1): a Resin that Displays Increased Alkali SolubilityUnder the Action of Acid>

A flask equipped with a stirrer, a reflux condenser, a thermometer, anda dropping funnel was flushed with nitrogen, and subsequently chargedwith propylene glycol methyl ether acetate as a solvent, and stirring ofthe solvent was then initiated. The temperature of the solvent was thenraised to 80° C. The dropping funnel was charged with2,2′-azobisisobutyronitrile as a polymerization catalyst, 20% by weightof 1-ethylcyclohexyl methacrylate as the structural unit (b1), and 80%by weight of 2-ethoxyethyl acrylate as the structural unit (b2), andfollowing stirring to dissolve the polymerization catalyst, theresulting solution was added dropwise to the flask at a uniform rateover 3 hours. Reaction was then continued for a further 5 hours at 80°C. to allow the polymerization to proceed. The temperature was thencooled to room temperature, yielding a resin (B-1) with a weight averagemolecular weight of 350,000.

Synthesis Example 2

<Synthesis of (B-2): a Resin that Displays Increased Alkali SolubilityUnder the Action of Acid>

With the exceptions of using 50% by weight of 1-ethylcyclohexylmethacrylate as the structural unit (b1), and 50% by weight of2-ethoxyethyl acrylate as the structural unit (b2), reaction wasconducted in the same manner as the synthesis example 1, yielding aresin (B-2) with a weight average molecular weight of 350,000.

Synthesis Example 3

<Synthesis of (B-3): a Resin that Displays Increased Alkali SolubilityUnder the Action of Acid>

With the exceptions of using 80% by weight of 1-ethylcyclohexylmethacrylate as the structural unit (b1), and 20% by weight of2-ethoxyethyl acrylate as the structural unit (b2), reaction wasconducted in the same manner as the synthesis example 1, yielding aresin (B-3) with a weight average molecular weight of 350,000.

Synthesis Example 4

<Synthesis of (B-4): a Resin that Displays Increased Alkali SolubilityUnder the Action of Acid>

With the exceptions of using 20% by weight of adamantyl acrylate as thestructural unit (b1), and 80% by weight of 2-ethoxyethyl acrylate as thestructural unit (b2), reaction was conducted in the same manner as thesynthesis example 1, yielding a resin (B-4) with a weight averagemolecular weight of 350,000.

Synthesis Example 5

<Synthesis of (B-5): a Resin that Displays Increased Alkali SolubilityUnder the Action of Acid>

With the exceptions of using 50% by weight of adamantyl acrylate as thestructural unit (b1), and 50% by weight of 2-ethoxyethyl acrylate as thestructural unit (b2), reaction was conducted in the same manner as thesynthesis example 1, yielding a resin (B-5) with a weight averagemolecular weight of 350,000.

Synthesis Example 6

<Synthesis of (B-6): a Resin that Displays Increased Alkali SolubilityUnder the Action of Acid>

With the exceptions of using 80% by weight of adamantyl acrylate as thestructural unit (b 1), and 20% by weight of 2-ethoxyethyl acrylate asthe structural unit (b2), reaction was conducted in the same manner asthe synthesis example 1, yielding a resin (B-6) with a weight averagemolecular weight of 350,000.

Synthesis Example 7

<Synthesis of (B-7): a Resin that Displays Increased Alkali SolubilityUnder the Action of Acid>

With the exceptions of using 50% by weight of 1-ethylcyclohexylmethacrylate as the structural unit (b1), and 50% by weight of2-ethoxyethyl acrylate as the structural unit (b2), reaction wasconducted in the same manner as the synthesis example 1, yielding aresin (B-7) with a weight average molecular weight of 50,000.

Synthesis Example 8

<Synthesis of (B-8): a Resin that Displays Increased Alkali SolubilityUnder the Action of Acid>

With the exceptions of using 50% by weight of 1-ethylcyclohexylmethacrylate as the structural unit (b1), and 50% by weight of2-ethoxyethyl acrylate as the structural unit (b2), reaction wasconducted in the same manner as the synthesis example 1, yielding aresin (B-8) with a weight average molecular weight of 500,000.

Synthesis Example 9

<Synthesis of a Novolak Resin (c1)>

m-cresol and p-cresol were mixed together in a weight ratio of 60:40,formalin was added to the mixture, and a condensation was then conductedunder conventional conditions using oxalic acid as a catalyst, thusyielding a cresol novolak resin. This resin was subjected tofractionation to remove the low molecular weight fraction, yielding anovolak resin with a weight average molecular weight of 15,000. Thisresin was labeled (C-1).

Synthesis Example 10

<Synthesis of a Copolymer (c2) Containing a Hydroxystyrene StructuralUnit and a Styrene Structural Unit>

With the exception of using 75% by weight of hydroxystyrene units and25% by weight of styrene units as the structural units, reaction wasconducted in the same manner as the synthesis example 1, yielding aresin (C-2) with a weight average molecular weight of 3,000.

Synthesis Example 11

<Synthesis of an Acrylic Resin (c3)>

With the exception of using 130 parts by weight of 2-methoxyethylacrylate, 50 parts by weight of benzyl methacrylate, and 20 parts byweight of acrylic acid as structural units, reaction was conducted inthe same manner as the synthesis example 1, yielding a resin (C-3) witha weight average molecular weight of 250,000.

Synthesis Example 12

<Synthesis of a Vinyl Resin (c4)>

A methanol solution of poly(vinyl methyl ether) (weight averagemolecular weight 50,000) (manufactured by Tokyo Kasei Kogyo Co., Ltd.,concentration: 50% by weight) was subjected to a solvent exchange topropylene glycol monomethyl ether acetate using a rotary evaporator,thus yielding a resin (C-4) as a solution with a concentration of 50% byweight.

Examples 1 to 13

<Preparation of Chemically Amplified Positive Photoresist Compositionsfor Thick Film>

The various components shown in Table 1 were mixed together in propyleneglycol monomethyl ether acetate to form a series of homogeneoussolutions, and each solution was then filtered through a membrane filterwith a pore size of 1 μm, thus yielding a chemically amplified positivephotoresist composition for thick film.

As the acid generator of the component (A), the following two compoundswere used.

(A-1):(5-propylsulfonyloxyimino-5H-thiophen-2-ylidene)-(2-methylphenyl)acetonitrile

(A-2): the compound represented by the chemical formula (8) shown below.

Furthermore, in Table 1, (D-1) represents salicylic acid, and (D-2)represents triethanolamine. The numerical values in Table 1 representthe number of parts by weight of each component. TABLE 1 Example 1 2 3 45 6 7 8 9 10 11 12 13 A-1 1 2 4 1 2 4 A-2 1 1 1 1 1 1 1 B-1 80 B-2 50 5050 50 50 50 B-3 20 B-4 80 B-5 50 B-6 20 B-7 50 B-8 50 C-1 50 50 50 20 2050 80 20 50 80 C-2 50 20 C-3 50 5 C-4 50 5 D-1 0.2 0.2 0.2 0.2 0.2 0.2D-2 0.2 0.2 0.2 0.2 0.2 0.2

Comparative Example 1

<Preparation of Chemically Amplified Positive Photoresist Compositionfor Thick Film>

3 parts by weight of an acid generator (A) (the compound represented bythe above chemical formula (8)); 100 parts by weight of a component (B)(comprising 67 parts by weight of a copolymer with a weight averagemolecular weight of 8,000, containing 67 mol % of hydroxystyrene units,22 mol % of styrene units, and 11 mol % of 1-ethylcyclohexylmethacrylate units, and 33 parts by weight of a copolymer containing 67mol % of hydroxystyrene units, 29 mol % of styrene units, and 4 mol % of1-ethylcyclohexyl methacrylate units); 0.1 parts by weight oftriethanolamine as a component (d1); and 0.1 parts by weight ofphenylphosphonic acid as a component (d2) were prepared, thesecomponents were dissolved in 300 parts by weight of ethyl lactate, afluorine-based surfactant [brand name: Fluorad FC-171 (manufactured by3M Corporation)] was added in a quantity equivalent to 1.0% by weightrelative to the total weight of the solution, and the solution was thenfiltered through a membrane filter with a pore size of 0.2 μm, thusyielding a positive resist composition.

Test Example 1

The characteristics of the chemically amplified positive photoresistcompositions produced in the examples and the comparative exampledescribed above were evaluated in the following manner.

Compatibility

Each composition was stirred for 12 hours at room temperature, and thestate of the solution immediately following completion of the stirring,and the state of the solution upon leaving the solution to stand for afurther 12 hours were observed visually. The state of the dispersion wasevaluated using the following criteria.

A: The composition was visually confirmed as being uniformly dispersedfollowing stirring for 12 hours, and remained uniformly dispersed afterstanding for 12 hours.

B: The composition was uniformly dispersed following stirring for 12hours, but underwent phase separation on standing for 12 hours.

C: The composition was not uniformly dispersed even after stirring for12 hours.

Coatability

Each composition was applied to a 5-inch gold sputtered wafer (a goldsubstrate) over a period of 25 seconds, using a spinner operating at1000 rpm, and the applied composition was then heated on a hotplate at110° C. for 6 minutes. The thus formed coating was inspected visually,and the coatability was evaluated using the following criteria.

A: The formed coating was uniform with no unevenness.

B: The formed coating was not uniform, and displayed poor planarity.

C: The formed coating displayed irregularities such as pinholes andcissing.

Developability, Resolution

Thick-film photoresist laminated products with coating films ofthickness 20 μm, 65 μm, and 120 μm were formed.

In the case of the coating films with a thickness of approximately 20μm, each composition was applied to a 5-inch gold sputtered wafer over aperiod of 25 seconds, using a spinner operating at 1800 rpm, so as toform a film thickness of approximately 20 μm, and was then prebaked on ahotplate at 110° C. for 6 minutes, thus forming a thick-film photoresistlaminated product.

In the case of the coating films with a thickness of approximately 65μm, each composition was applied over a period of 25 seconds at 800 rpm,and prebaked on a hotplate at 110° C. for 1 minute, before an additionalapplication for 25 seconds at 800 rpm and subsequent prebaking at 110°C. for 12 minutes, thus forming a thick-film photoresist laminatedproduct.

Furthermore, in the case of the coating films with a thickness ofapproximately 120 μm, each composition was first applied over a periodof 25 seconds at 800 rpm and prebaked on a hotplate at 110° C. for 1minute, then once again applied for 25 seconds at 500 rpm and prebakedon a hotplate at 110° C. for 1 minute, before a final application for 25seconds at 500 rpm and subsequent prebaking at 110° C. for 20 minutes,thus forming a thick-film photoresist laminated product.

Each of the thus formed thick-film photoresist laminated products wasexposed with ultraviolet radiation through a pattern mask used formeasuring resolution, at exposure doses ranging in a stepwise mannerfrom 100 to 10,000 mJ/cm², using a stepper device (NSR-2005i10D,manufactured by Nikon Corporation). Following exposure, the product washeated at 70° C. for 5 minutes, and was then developed in a developingsolution (brand name: P-7G from the PMER series, manufactured by TokyoOhka Kogyo Co., Ltd.).

The developed product was washed under running water, and blown withnitrogen to yield a pattern-wise cured product. This cured product wasinspected under a microscope, and the developability and resolution wereevaluated using the following criteria.

A: A pattern with an aspect ratio of 2 or greater was generated at oneof the above exposure doses, and no residues were visible.

C: Either a pattern with an aspect ratio of 2 or greater was notgenerated, or residues were visible.

The aspect ratio represents the value of (the height of the patternedresist divided by the width of the patterned resist).

Plating Solution Resistance

The substrates comprising the pattern-wise cured product prepared forthe evaluation of developability and resolution were used as testspecimens. Each test specimen was subjected to ashing treatment using anoxygen plasma, was subsequently immersed in a gold sulfite platingsolution at 65° C. for 40 minutes, and was then washed under runningwater, yielding a treated test specimen. The state of the bumps and thepattern-wise cured product formed on the surface of the treated testspecimen were inspected using an optical microscope or an electronmicroscope, and the resistance of the pattern-wise cured product to theplating solution, the shape of the formed bumps, and the resistance ofthe pattern-wise cured product to the plating process were evaluatedusing the following criteria.

A: The state of the formed bumps and the pattern-wise cured productrevealed no particular changes, and the formed bumps and thepattern-wise cured product were favorable.

C: Cracking, swelling, or chipping occurred in the pattern-wise curedproduct, or the surface of the pattern-wise cured product appeared veryrough.

Bump Shape

A treated test specimen was prepared in the same manner as for theplating solution resistance evaluation, the state of the bumps and thepattern-wise cured product formed on the surface of the treated testspecimen were inspected using an optical microscope or an electronmicroscope, and the shape of the formed bumps was evaluated using thefollowing criteria. Furthermore, in those cases where the bump shape wasfavorable, the angle between the substrate and the bumps, and the errorratio relative to the mask dimensions were also measured.

A: The shapes of the bumps were favorable, and displayed good dependenceon (good tracking of) the pattern-wise cured product.

C: The shapes of the bumps appeared swollen, and were independent of thepattern-wise cured product.

Releasability

The substrates comprising the pattern-wise cured product prepared forthe evaluation of developability and resolution were used as testspecimens. Each test specimen was immersed for 10 minutes in a stirredstripping solution at 70° C. (Stripper 104, manufactured by Tokyo OhkaKogyo Co., Ltd.), was subsequently rinsed with alcohol to remove thepattern-wise cured product, and was then inspected, either visually orunder an optical microscope, and evaluated using the following criteria.

A: No residues of the pattern-wise cured product were visible.

C: Residues of the pattern-wise cured product were visible.

Photosensitivity

Coating films of each of the various film thickness values were formedon 5-inch silicon wafers, and each coating film was exposed withultraviolet radiation in sections, through a pattern mask used formeasuring resolution, at exposure doses ranging from 100 to 10,000mJ/cm², using a stepper device (NSR-2005i10D, manufactured by NikonCorporation). The exposed coating film was then developed in adeveloping solution (brand name: P-7G from the PMER series, manufacturedby Tokyo Ohka Kogyo Co., Ltd.). The developed product was washed underrunning water, and blown with nitrogen to yield a pattern-wise curedproduct. This cured product was inspected under a microscope, and theminimum exposure dose required to form a pattern with an aspect ratio of2 or greater, with no visible residues, in other words, the minimum doserequired to form a pattern, was measured.

Each of the above evaluations was performed for each positivephotoresist composition prepared in the examples 1 to 13, and thecomparative example 1. The results are shown in Table 2. TABLE 2Comparative Example example 1 2 3 4 5 6 7 8 9 9 9 10 11 12 13 1Compatibility A A A A A A A A A A A A A A A A Coatability A A A A A A AA A A B A A A A B Film thickness  20  20  20  20  20  20  20  20  20  65 120  20  20  20  20  20 Developability A A A A A A A A A A A A A A A APlating solution A A A A A A A A A A A A A A A C resistance Bump shape AA A A A A A A A A A A A A A C Releasability A A A A A A A A A A A A A AA Photosensitivity 300 300 300 300 300 300 300 500 500 2000 5000 500 600600 600 1000

While preferred embodiments of the invention have been described andillustrated above, it should be understood that these are exemplary ofthe invention and are not to be considered as limiting. Additions,omissions, substitutions, and other modifications can be made withoutdeparting from the spirit or scope of the present invention.Accordingly, the invention is not to be considered as being limited bythe foregoing description, and is only limited by the scope of theappended claims.

1. A chemically amplified positive photoresist composition for thickfilm that is used for forming a thick-film photoresist layer with a filmthickness of 10 to 150 μm on top of a support, comprising: (A) acompound that generates acid on irradiation with active light orradiation; (B) a resin that displays increased alkali solubility underaction of acid; and (C) an alkali-soluble resin; wherein said component(B) comprises a resin formed from a copolymer containing a structuralunit (b1) represented by a general formula (1) shown below:

(wherein, R¹ represents a hydrogen atom or a methyl group, R² representsa lower alkyl group, and X represents a group which, in combination witha carbon atom bonded thereto, forms a hydrocarbon ring of 5 to 20 carbonatoms).
 2. A chemically amplified positive photoresist composition forthick film according to claim 1, wherein said component (B) is a resincomprising a copolymer containing said structural unit (b1), and astructural unit derived from a polymerizable compound containing anether linkage (b2).
 3. A chemically amplified positive photoresistcomposition for thick film according to claim 2, wherein saidpolymerizable compound containing an ether linkage (b2) is a compoundrepresented by a general formula (7) shown below, or phenoxypolyethyleneglycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, ortetrahydrofurfuryl (meth)acrylate:CH₂═C(R′)COO—(C_(m)H_(2m)—CHR¹⁰—O)_(n)—R″  (7) (wherein, R′ represents ahydrogen atom or a methyl group, R¹⁰ represents a hydrogen atom or analkyl group of 1 or 2 carbon atoms, R″ represents an alkyl group or arylgroup of 1 to 7 carbon atoms that may also contain an oxygen atom, mrepresents an integer of either 1 or 2, and n represents an integer from1 to 10).
 4. A chemically amplified positive photoresist composition forthick film according to claim 1, wherein relative to 100 parts by weightof a combined weight of said component (B) and said component (C), aquantity of said component (A) is within a range from 0.1 to 20 parts byweight, a quantity of said component (B) is within a range from 5 to 95parts by weight, and a quantity of said component (C) is within a rangefrom 5 to 95 parts by weight.
 5. A chemically amplified positivephotoresist composition for thick film according to claim 1, whereinsaid component (C) comprises at least one resin selected from the groupconsisting of (c1) novolak resins, (c2) copolymers containing ahydroxystyrene structural unit and a styrene structural unit, (c3)acrylic resins, and (c4) vinyl resins.
 6. A chemically amplifiedpositive photoresist composition for thick film according to claim 1,further comprising: an acid diffusion control agent (D).
 7. A thick-filmphotoresist laminated product, comprising: a support; and a thick-filmphotoresist layer with a film thickness of 10 to 150 μm, formed from achemically amplified positive photoresist composition for thick filmaccording to claim 1, laminated on top of said support.
 8. A thick-filmphotoresist laminated product, comprising: a support; and a thick-filmphotoresist layer with a film thickness of 20 to 120 μm, formed from achemically amplified positive photoresist composition for thick filmaccording to claim 1, laminated on top of said support.
 9. Amanufacturing method for a thick-film resist pattern, comprising: alamination step for producing a thick-film photoresist laminated productaccording to claim 7; an exposure step for selectively irradiating saidthick-film photoresist laminated product with active light or radiation;and a developing step for conducting post exposure developing to producea thick-film resist pattern.
 10. A manufacturing method for a connectionterminal, comprising: a step for forming a connection terminalcomprising a conductor on a resist-free portion of a thick-film resistpattern produced using a manufacturing method for a thick-film resistpattern according to claim
 9. 11. A manufacturing method for aconnection terminal according to claim 10, wherein a depth of saidresist-free portion is within a range from 10 to 150 μm.